At midnight on the first day a great drum sounds. From then on it does not stop for seventy-two hours, night or day.

Iyozu-hiko-no-mikoto Shrine, in the southern outskirts of Matsuyama. Everyone calls it Tsubaki-san — the camellia shrine. For three days from the seventh day of the first lunar month, a kilometre of the prefectural road leading to it is closed to traffic and lined with some eight hundred stalls. Half a million people pass through.

On the middle day the portable shrine goes out. But until it has left the grounds the bearers make no sound at all, and do not sway it, as bearers everywhere else in Japan do. The god, they say, is stepping out in secret. They call it the hidden procession.

This is the festival that calls spring to the Iyo road. When it is over, the cold is said to have passed its peak; the farming off-season ends, and across Shikoku people begin turning the soil and sowing seed. The shrine itself puts it plainly: the date was fixed to the first waxing moon nearest the start of spring, which is why it moves — by nearly three weeks across three years.

A festival as a mark on the calendar. When it is done, you go out to the fields.